1. Field of the Invention
The present invention relates to fast-rise-time microwave signal devices and more particularly to a nanosecond rf envelope generator or pulse shaping network that is passive, in-line, and broadband.
2. Description of the Prior Art
Fast-rise-time, high power microwave (HPM) pulses from high performance radars may be able to pass through electronic protection devices such as diode limiters before these devices turn on, thereby potentially damaging receiver from ends. The pulse leaking past a protection device may be quite short in duration and significantly high in power (10 to 100 kW). Devices like PIN diode limiters, terminal protection devices and other similar systems react differently when subjected to these fast rising, short duration, pulses. Studying the spike leakage and damage threshold of these devices is necessary so that they can be optimally protected. Consequently, there is a great need to test these electronic systems with fast-rise-time, short duration, HPM pulses in order to understand and improve their immunity.
Present devices for forming short duration rf pulses from "long duration" rf signals include diode switches and laser switched semiconductors. However, diode switches only work at low power and laser switched semiconductors require a large and expensive laser.
From the above, it may be appreciated that there is a great need for an easy to use device that produces a short duration, HPM pulse for testing purposes.